1. Field of the Invention
The present invention relates to a slide fastener chain in which fastener elements of injection type are attached to opposing side edges of a pair of fastener tapes by injection molding means using synthetic resin.
2. Description of the Related Art
In a fastener element of injection type according to Japanese Utility Model Publication No. 63-7049, as shown in FIG. 12, fastener elements 102 of injection type are attached to opposing side edges 106 of a pair of fastener tapes 104 by injection molding means using synthetic resin such that the front surface and rear surface of each of the fastener elements 102 have different shapes. In the front surface, a leg portion 130 is provided projectingly from a proximal end 140 of the fastener element 102 to a front end thereof, a neck portion 116 is provided in the middle of the leg portion 130, and an expanded coupling head 117 is provided at a front end of the neck portion 116 continuously, and a supporting portion 112 substantially triangular in its plan view, that is, a supporting portion 112 whose lateral width decreases gradually, is provided on the bottom face of the leg portion 130 so as to extend from a beginning point of the neck portion 116 to the front end thereof, the thickness thereof being smaller than that of the leg portion 130 on the upper portion. As a consequence, right and left fastener elements 102 engage each other by the neck portions 116 on the upper portion.
The fastener element 102 of injection type as shown in FIG. 12 is provided with a leg portion 130 on the front surface of the fastener element 102 such that the leg portion 130 extends from the proximal end 140 to the front end, and a constricted neck portion 116 is provided in the middle of the leg portion 130. An expanded coupling head 117 is provided at the front end following the neck portion 116, and a substantially triangular supporting portion 112 in its plan view is provided on the bottom side of the leg portion 130 so as to extend from the neck portion 116 to the front end, the supporting portion 112 being thinner than the leg portion 130 of the upper portion. Therefore, both the front surface and rear surface are formed into a flat plane, thereby providing such a problem that the tactile feeling received from the fastener element 102 is not favorable.
The present invention has been achieved in views of the above-described problem, and a main object of the invention is to provide a slide fastener chain in which the surface on the front surface side of an injection-type fastener element in the fastener chain is formed into a curved face, that is, a circular arc shape, thereby improving a tactile feeling received from the fastener element and securing an improvement of a beautiful appearance in its fastener element row.
Further object of the present invention is to provide the slide fastener chain, wherein the front side and rear side of the injection type fastener element have different shapes, and the surface of the fastener element disposed on the front side is formed into a curved face, thereby securing an excellent tactile feel.
Further object of the present invention is to provide the slide fastener chain, wherein the front surface of the fastener element whose front side and rear side are formed into the same contour is formed into a curved face, thereby securing an excellent tactile feeling.
Further object of the present invention is to provide the slide fastener chain, wherein the curved face formed on the surface of the fastener element in the fastener chain is formed in the width direction of the fastener element, that is, in the longitudinal direction of the fastener element row, thereby securing an excellent tactile feeling.
Further object of the present invention is to provide the slide fastener chain, wherein the curved face formed on the surface of the fastener element in the fastener chain is formed in the length direction of the fastener element, that is, in the horizontal direction of the fastener element row, thereby securing an excellent tactile feeling.
Further object of the present invention is to provide the slide fastener chain, wherein the curved face formed on the surface of the fastener element in the fastener chain is formed in the width direction and the length direction of the fastener element, that is, both in the longitudinal direction and horizontal direction of the fastener element row, thereby securing an excellent tactile feeling.
Further object of the present invention is to provide the slide fastener chain, wherein an excellent curved face is formed on the surface of the fastener element by limiting a value of a curvature radius of the curved face formed on the surface of the fastener element, thereby securing an excellent tactile feeling.